Convert numbers between Roman numerals, decimal, binary, hexadecimal, and octal. Enter a value in any format and see all others instantly.
Open Universal Number Converter → free, no sign-inRoman numerals, decimal, binary, hexadecimal, and octal — all five number representation systems in one tool. Enter a number in any of them and instantly see the equivalent in all the others, with validation to catch values that aren't valid in the selected system.
Computer science students learning number systems, developers needing quick cross-base conversions, historians working with Roman numeral dates, or anyone who needs to convert between multiple number representations at once.
No tutorials. No learning curve. Open it and get started.
No server uploads. Includes Roman numerals alongside the computational bases — an unusual but useful combination.
Completely free. No trial period. No premium tier for basic functionality. No account required. Use it as often as you need.
One job, done well. Universal Number Converter was built to solve a specific problem cleanly. No feature bloat, no ads, no distractions.
What is the maximum Roman numeral?
Standard Roman numerals go up to 3,999 (MMMCMXCIX). This tool handles the standard range.
What is octal used for?
Octal (base 8) is used in Unix/Linux file permissions (e.g. chmod 755 = binary 111 101 101).
Are hexadecimal letters case-sensitive?
Both uppercase and lowercase A-F are accepted.
Can I convert negative numbers?
Roman numerals and some representations don't support negatives — this tool covers positive integers.
What is binary?
Base 2 — uses only 0 and 1. The fundamental representation of data in all digital computing.
Free. Instant. No sign-in. Open it and get the job done.
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